{"id":"CVE-2026-107297","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-107297","generatedAt":"2026-10-28T10:48:17.503Z","title":"A remote peer can split one valid MessagePack container across many small chunks, causing completed elements to be decoded repeatedly, producing quadratic CPU use and blocking the event loop.","description":"msgpack5 is a msgpack v5 implementation for node.js and the browser. Prior to 6.1.0, the streaming decoder reparses an incomplete array or map from the beginning whenever another chunk arrives. A remote peer can split one valid MessagePack container across many small chunks, causing completed elements to be decoded repeatedly, producing quadratic CPU use and blocking the event loop. This issue is fixed in version 6.1.0.","published":"2026-10-08T17:17:16.000Z","lastModified":"2026-10-08T20:48:37.000Z","status":"Deferred","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":5.9,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H"},"cwe":["CWE-407"],"affected":[],"epss":{"score":0.00389,"percentile":0.328,"date":"2026-10-27","history":[{"date":"2026-10-09","score":0.00389,"percentile":0.30898}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.39%). Track it; it rarely justifies an emergency change on its own."},"changes":[{"kind":"new","label":"New CVE","at":"2026-10-08T17:17:16.000Z","detail":{"score":"5.9","severity":"MEDIUM","publishedAt":"2026-10-08T17:17:15.550Z"},"summary":"New CVE, medium severity (CVSS 5.9)."}],"references":[{"url":"https://github.com/mcollina/msgpack5/commit/e4827641d3105e295cbbd56e9c5389978547eab4","source":"security-advisories@github.com"},{"url":"https://github.com/mcollina/msgpack5/releases/tag/v6.1.0","source":"security-advisories@github.com"},{"url":"https://github.com/mcollina/msgpack5/security/advisories/GHSA-gcx5-hxj7-gpqq","source":"security-advisories@github.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-107297","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}